This is because when you compare dances
performed at different times of the day, you need to account for the changes in the sun’s azimuth. To estimate the
direction of the advertised foraging site measure first the average angles of 4
waggle-runs by using a radial protractor over the
screen. Such average angle was added to the sun azimuth angle at the solar time
when the dance was captured. The sun azimuth angle for each dance can be
calculated using the world-wide web (e.g. http://aa.usno.navy.mil/data/docs/AltAz.php#formb).

The foraging sites exploited at a social scale
can be estimated by a systematic recording of the dance orientation in the
whole colony. If video recordings are made systematically, this parameter is
especially useful for analysing collective honey bee foraging under natural
conditions.